Partially substituting alfalfa hay with hemp forage in the diet of goats improved feed efficiency,ruminal fermentation pattern and microbial profiles

The use of hemp as a forage source in livestock diets has been less studied because bioactive residues in animal tissues may pose a risk to consumers.This study investigated the effects of partial substitution of alfalfa hay(AH)with hemp forage(HF)in growing goat diets on growth performance,carcass traits,ruminal fermentation characteristics,rumen microbial communities,blood biochemistry,and antioxidant indices.Forty Xiangdong black goats with body weight(BW)7.82±0.57 kg(mean±SD)were grouped by BW and randomly assigned into one of the four treatment diets(n=10/treatment)in a completely randomized design.The goats were fed ad libitum total mixed rations containing 60%forage and 40%concentrate(DM basis).The diets included control(CON;60%AH and 40%concentrate),55%AH and 5%HF(HF5),50%AH and 10%HF(HF10),and 40%AH and 20%HF(HF20).Increasing the substitution of HF for AH linearly decreased(P=0.004)DM intake and improved feed conversion efficiency.However,final BW,average daily gain,carcass traits,meat quality,and most blood biochemistry indices did not differ among treatments.The ruminal NH3-N concentration(P=0.003)and blood urine nitrogen(P=0.050)linearly increased(P<0.01)with increasing substitution rate of HF,whereas the total volatile fatty acids concentration quadratically changed(P=0.007).Substitution of AH with HF had no effect on the diversity and richness of ruminal microbes,though it linearly decreased(P=0.040)Prevotella_1 and linearly increased(P=0.017)Rike-nellaceae_RC9_gut_group.The cannabinoids and/or their metabolites were detected in both ruminal fil-trates(8)and plasma(4),however,no detectable cannabinoid-related residues were observed in meat.These results indicate that the HF could be used to partially substitute AH in goat diets,whereas the effects vary between substitution rates of HF for AH.Although no cannabinoid-related residues were detected in meat,the presence of cannabinoids residues in blood warrants further study of HF feeding to confirm the cannabinoids residues are not present in the animal products.

Substitution of ramie (Boehmeria nivea) for alfalfa in improving the carcass and meat quality of Liuyang Black goats

Ramie(Boehmeria nivea)is noted for the production of a large biomass that has a high protein content and is rich in antioxidants.It may thus serve as a high-quality forage material to replace alfalfa and improve the meat quality of farmed animals.In this study,we evaluated the carcass characteristics and meat quality of goats when 0,35%,75%,and 100%of dietary alfalfa was replaced with ramie.Crude protein content(linear,P<0.0001)and key muscle color values at 24 h after slaughter decreased with increasing ramie levels.The content of most individual amino acids,non-essential amino acids(NEAA),total amino acids(TAA),branched chain amino acids(BCAA),functional amino acids(FAA),and flavor amino acids(DAA)decreased(P<0.05)with increasing dietary ramie.The diet in which 35%of alfalfa was replaced with ramie yielded meat with the highest amino acid content,whereas the fatty acid profile was unaffected by the inclusion of ramie.These results indicate that ramie could be used as a potential dietary forage resource for goats,and that substituting 35%of alfalfa with ramie,which is equivalent to 126 g/kg DM content,would be optimal in terms of goat meat quality.